Jef - March 11 2025
9 Amazing Uses for Coffee Grounds: Don't Throw Them Away, Turn Waste into Treasure!
Coffee is the second most consumed beverage in the world after water. In daily life, people usually discard coffee grounds after brewing coffee, but only about 30% of the coffee bean is extracted into the coffee we drink.
Coffee grounds are a byproduct of coffee brewing. They are biodegradable and contain many beneficial components. Many people are unaware that coffee grounds have numerous practical and creative uses. The next time you enjoy a delicious cup of coffee, consider keeping the grounds and repurposing them! Here are 9 incredible uses—check them out!
FIGURE 1
FIGURE 1. Number of publications from the Web of Science database from 2010 to 2021 based on the topic search category.
(A) ‘spent coffee ground*’,
(B) ‘spent coffee ground*’ and ‘pellet’,
(C) ‘spent coffee ground*’ and ‘biodiesel’,
(D) ‘spent coffee ground*’ and ‘biorefinery.’
1. Natural Cleaner
Coffee grounds contain fine particles and natural acidic properties, making them an ideal natural cleaner. Their strong adsorption ability helps remove grease and stubborn stains. Research shows that coffee grounds can eliminate oil, grime, and even tough stains on kitchen countertops. Simply mix coffee grounds with water, apply to the stained surface, scrub gently, and rinse with clean water. Since they contain no harmful chemicals, coffee grounds provide an environmentally friendly and safe cleaning method.
TABLE 1
TABLE 1. Recent studies on elemental compositions of SCGs.
2. Pleasant Aromatherapy
The unique and long-lasting aroma of coffee grounds makes them an excellent natural fragrance. They can be used in incense burners or scented candles to emit a warm and inviting fragrance. Studies show that coffee aroma contains compounds such as aldehydes and phenols, which have calming effects that help reduce stress and improve mood. Simply place dried coffee grounds in an incense burner or mix them with beeswax to make scented candles, adding a unique ambiance to your home.
3. Reducing Puffy Eyes
Coffee grounds contain caffeine, which has antioxidant properties that help reduce puffiness around the eyes. Caffeine constricts blood vessels and reduces swelling, which is why it is widely used in eye creams and skincare products. If you experience eye fatigue or puffiness, wrap cooled coffee grounds in a cloth and apply them to the eye area for 15-20 minutes. This can effectively reduce discomfort and diminish under-eye bags.
4. Natural Exfoliant
With their moderate-sized granules, coffee grounds serve as an excellent natural exfoliator, gently removing dead skin and impurities. Research indicates that coffee grounds are rich in antioxidants such as chlorogenic acid, which helps the skin fight free radicals and improve circulation. Mixing coffee grounds with olive oil or coconut oil and massaging onto the skin can effectively remove dead skin cells, leaving your skin smooth and refreshed.
Ani Dimi/Stocksy
5. Powerful Deodorizer
Coffee grounds have excellent odor-absorbing properties, especially for eliminating unpleasant smells in refrigerators, shoe cabinets, or wardrobes. Their strong adsorption ability allows them to remove odors from food, smoke, and mold. Studies show that coffee grounds can absorb and neutralize harmful substances like formaldehyde and volatile organic compounds (VOCs), purifying indoor air. Simply place dried coffee grounds in a breathable container or small fabric bag to keep your space fresh.
Raw SCGs have been used for absorption of different pollutants. Yen et al., 2022 studied polystyrene particles adsorption and obtained a maximum efficiency of 74%. SCGs have also seen use for removing cadmium (Azouaou et al., 2010; Palma et al., 2017; Kim and Kim, 2020) and other heavy metals (Hao et al., 2017). SCG can absorb ozone but was less effective than activated carbon (Hsieh and Wen, 2020). Loffredo et al., 2020 compared SCGs adsorption performance with other biomass and other adsorbents (wood biochar, and hydrochar) on the adsorption effectiveness of ochratoxin A. SCG performed worse than wood biochar, hydrochar, humic acid, clementine peel and coconut fiber, but was than ground almond shells, hazelnuts, walnuts, and chestnuts. SCGs have also been used for dye adsorption (Safarik et al., 2012), and the effectiveness was highly dependent on dye type. Direct SCG and SCG biochar use for remediating heavy metal contaminated soil and water were compared by Kim et al., 2014. While both reduced the heavy metal bioavailability; the direct SCG use actually increased phytotoxicity, unlike the biochar. SCGs in these studies are usually washed and dried, but the performance was not as good as biochar or activated carbon.
Reference：A Review of Recent Advances in Spent Coffee Grounds Upcycle Technologies and Practices
6. Natural Hair Conditioner
Coffee grounds are highly beneficial for hair care, promoting healthy hair growth and adding shine. The caffeine in coffee grounds stimulates scalp circulation, encourages hair growth, and strengthens hair strands. Mixing coffee grounds with conditioner and massaging it into your scalp for 5-10 minutes before rinsing can help remove dandruff and leave your hair silky smooth.
7. Natural Insect Repellent
The strong scent of coffee grounds repels many insects, especially ants, silverfish, and snails. Studies have found that certain compounds in coffee grounds disrupt insects' olfactory systems, keeping them away. Sprinkle coffee grounds around doorways, windowsills, or plant bases to prevent insect invasions. This is a non-toxic, eco-friendly alternative to chemical repellents.
SCG can function as mulch, compost, fertilizer, or even pest repellant in gardens (Chalker-Scott, 2009). An urban university in Midwest US collected compost SCGs, together with yard waste.
8. Melting Ice and Snow
During cold winters, coffee grounds can help melt snow and ice. Their acidic properties lower the freezing point of ice, accelerating the melting process. Studies have shown that sprinkling coffee grounds on icy roads reduces snow buildup and prevents slipping accidents, ensuring safer walkways.
9. Natural Plant Fertilizer
Coffee grounds are rich in nitrogen, phosphorus, and potassium—essential nutrients for plant growth—making them an excellent organic fertilizer. Nitrogen promotes plant growth, while phosphorus and potassium support root development and disease resistance. Studies indicate that adding coffee grounds to the soil of flowers and vegetables provides additional nutrients, encouraging healthy plant growth. Additionally, coffee grounds improve soil structure by enhancing aeration and drainage.
SCG is less than 30% and coffee filters remained in the pile as a carbon source. The compost pile is mechanically turned regularly and matures (color changing from light to dark) within 6 months to a year and is used for university landscapes and teaching gardens. SCG can be mixed with other components to be used as fertilizer and was found to enhance grapevine production (Ronga et al., 2020). SCG is also co-composted with manure or sludges and used for soil amendment (Emmanuel et al., 2017) SCG is rich in nitrogen and other organic materials and can be a potential medium to increase soil organic matter. However, the smaller particle size can be an issue for blocking water and air circulation when used as mulch.
Reference：A Review of Recent Advances in Spent Coffee Grounds Upcycle Technologies and Practices
Conclusion
Coffee grounds are more than just a byproduct of brewing coffee—they have countless uses beyond what you might expect. From cleaning solutions to plant fertilizers, their unique properties bring numerous benefits to daily life. Next time you finish your coffee, consider reusing these valuable coffee grounds to reduce waste and contribute to a more sustainable environment!
*References
Frontiers | A Review of Recent Advances in Spent Coffee Grounds Upcycle Technologies and Practices
Available at:
https://www.frontiersin.org/journals/chemical-engineering/articles/10.3389/fceng.2022.838605/full
